The debut of the Ferrari-powered car had been delayed because of a last-minute technical glitch that was discovered before the car was dispatched from its Banbury factory.
But after curing the issue, Marussia was able to transport its car to Jerez and get it ready to join the penultimate day of action.
The new car has been two years in the creation and is an all-new concept - which features new front and rear suspension designs.
Chief designer John McQuilliam said he was happy with the way the project had come together.
"We have benefitted enormously from the stability of our design teams, with the same personnel beginning - and now concluding - the process over a 24 month period," he said.
"I think we can feel justifiably proud of the way we have responded to such a significant challenge and the quality of car we have arrived at with the MR03.
"The car has been manufactured and finished to a very high standard, whilst achieving our most significant weight-saving targets to date and, importantly, with a crucial eye towards maintaining our excellent record of reliability."
Marussia finished 10th in last year's constructors' championship and it hopes that a switch to Ferrari power for 2014 will allow it to improve its competitiveness this year.
But team principal John Booth admits that the uncertainty created by the new 2014 regulations mean making firm predictions is quite hard.
"We have to temper the fact that there are a great many unknowns this season with the fact that we are, by nature, a highly ambitious team that is always demanding more of itself," he said.
"The target is to keep moving forward and that means being in a position where we no longer have to focus on the threat from behind and, instead, take the fight to the teams ahead.
"It is very early days to be speculating about relative performance though and that is something we can perhaps only speak with confidence about in Australia in 45 days' time."